Earthweek

A new study finds that green sea turtle colonies in the northern Great Barrier Reef are hatching almost exclusively females.

Arctic churnings

Dramatic climate change in the Arctic during the past few years is threatening to have significant impacts on the region's coastal food webs and animal populations, a new study by the Woods Hole Oceanographic Institution reveals.

Researchers found that the record melt of sea ice has increased wave action on the shallow Arctic coastal shelves, which is likely stirring up nutrients, carbon and other chemicals stored in the coastal sediment.

The scientists made the conclusion after finding levels of radium-228 in the middle of the Arctic Ocean had doubled over the past decade.

Researchers believe the naturally occurring isotope also was stirred up by the increased coastal wave action and carried across the polar region by ocean currents.

Climate survival

The continued existence of the human species is now threatened more by extreme weather in a changing climate than by weapons of mass destruction, according to a global survey by the World Economic Forum.

It was released just prior to the foundation's annual meeting of global leaders in Davos, Switzerland.

The survey of nearly 1,000 international experts and decision-makers reveals that in terms of likelihood and impact, extreme weather around the world is listed as the top concern.

The survey points to how catastrophic hurricane damage and wildfires last year demonstrate that environmental events can result in devastation of crucial infrastructure and food supplies.

Tropical cyclones

Cyclone Berguitta became the strongest storm to lash the Indian Ocean island of Mauritius since 2002.

Tropical storm-force Cyclone Joyce drenched northwestern Australia.

Earthquakes

A powerful temblor in southern Peru left at least two people dead and wrecked nearly 200 adobe homes.

Earth movements also were felt in central Portugal, the Greek capital of Athens, eastern Afghanistan, southern Myanmar, northern Taiwan and around Christchurch, New Zealand.

Warming demographics

One of the world's largest sea turtle colonies is becoming almost entirely female due to a warming climate.

Scientists from the United States and Australia write in the journal Current Biology that sand temperatures determine the gender of turtle hatchlings.

And since warmer temperatures result in more females, virtually no male turtles are hatching on the hotter nesting beaches of Australia's northern Great Barrier Reef.

This is the first direct evidence that global warming is altering the gender of sea turtle offspring.

Sea turtles are among the most ancient species roaming the world's oceans, and they have adjusted to shifting climates through the ages. But the modern climate may be changing more quickly than turtles can adjust to it.

Collateral damage

Wildlife in more than 70 percent of Africa's nature preserves was decimated by the ravages of war between 1946 and 2010, causing populations to enter what a new report describes as a "downward spiral."

Writing in the journal Nature, Joshua Daskin and Robert Pringle of Princeton University point to the deaths of 90 percent of the large herbivores in Mozambique's Gorongosa National Park during that country's decadeslong struggle for liberation from Portugal and subsequent civil war.

The decline in wildlife across Africa also has been compounded by poaching for ivory, hides and other animal parts, often sold on the black market to purchase weapons.

Eruption

Long streams of lava flowing down the slopes of Mayon volcano in the Philippines prompted more than 34,000 people to flee the eruption.

Plumes of ash also fell on several nearby villages, threatening to contaminate crops and water supplies.